Surrounding rock excavation damage analysis method under thermal-mechanical coupling condition and application thereof

Abstract

The invention discloses a surrounding rock excavation damage analysis method under a thermal-mechanical coupling condition and application thereof, and the analysis method comprises the steps: building an excavation blasting-unloading-cooling whole-process model of a tunnel, and solving a process control equation comprising thermal stress, dynamic stress and ground stress superposition coupling; therefore, rock heat-force coupling responses of the model under different geological conditions and excavation modes are obtained. The distribution range of the excavation damage area can be determined, the formation stage and the formation reason of rock mass damage can be disclosed, meanwhile, the analysis method has the advantages of being high in calculation efficiency, short in needed time, small in consumed manpower and material resources and the like, and prediction and guidance can be provided for adaptive excavation design of the chamber under the high-temperature and high-pressure conditions.

Description

technical field [0001] The invention relates to the technical field of underground chamber excavation. Background technique [0002] With the depletion of shallow mineral resources on the surface, resource exploration and mining activities continue to go deep into the earth. However, according to reports by Lucier et al., the measured ground stress level in a gold mine in South Africa can reach up to 100 MPa. According to the research of Belle and Biffi, the ground temperature gradient currently exposed in a coal mine in Australia is as high as 7°C / 100m. It can be seen that the high ground stress and high ground temperature caused by the increase in the depth of resource occurrence constitute a serious technical challenge for deep geotechnical engineering practices such as deep resource mining, deep energy development, and geological disposal of high-level radioactive waste. [0003] During the excavation of underground chambers, the retained rock mass will suffer from irre...

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Problems solved by technology

[0005] (1) Numerical calculations are usually limited by the grid division method. If the model is divided into dense grids, the calculation efficiency will be low and the time required will be long; if the model grids are coarse, the accuracy of the calculation results will not be effective. ensure;

[0006] (2) The thermal-mechanical coupling response of the rock under the coupling effect of high geostress and high geotemperature is not considered, so it is impossible to describe the damage evolution mechanism of surrounding rock excavation under the condition of deep high temperature and high pressure, and it is impossible to obtain an accurate operation plan under this condition

[0008] (1) The layout of acoustic monitoring points is relatively cumbersome, the monitoring process takes a long time, and consumes a lot of manpower and material resources

[0009] (2) The actual monitoring method can only obtain the distribution range of the surrounding rock damage area, but cannot reflect the rock stress evolution trend during the blasting-unloading-cooling process, and thus it is difficult to reveal the formation mechanism and mechanical mechanism of excavation damage, and cannot obtain accurate operation plan

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